In the high volume series production of motor vehicles on an assembly line, air-filled mounted tires or wheel-tire combinations comprising a tire mounted on a wheel rim, are prepared in a tire mounting production line and are then transported to the motor vehicle assembly line, where they are mounted on the respective motor vehicle. To prepare a mounted tire or wheel-tire combination, first the tire is loosely mounted on the wheel rim, and this assembly is then delivered to a tire filling station where the wheel-tire combination is inflated or filled with air. Then the inflated wheel-tire combination is generally tested for its running characteristics or any existing unbalance condition, and is generally also subjected to a balancing operation. In this regard, the tire filling station may be a component of the tire mounting system and/or of the wheel balancing system. The finished mounted tire or wheel-tire combination is then delivered from the tire production line to the assembly line for the assembly of the motor vehicle, where the wheel-tire combinations are mounted on the motor vehicles.
In the above context, mounted wheel-tire combinations having different diameters must be processed through the tire production line, especially when different vehicles are being assembled along the vehicle assembly line. It is thus important that the equipment of the tire production line, including the tire filling station, is adaptable to wheels or tires having various different diameters to achieve an efficient production and economy of the capital investment in the tire filling station.
A conventional tire filling station and tire filling method of a type generally described above are known from the German Patent DE 100 07 019 and the counterpart U.S. Pat. No. 6,467,524 (Ronge et al.—October 2002). According to this patent reference, the loosely assembled wheel-tire combination is delivered into the tire filling station so that one of the sidewall surfaces of the tire is oriented facing downwardly and makes sealing contact on a support plate. In other words, the tire lies flat on its side on the support plate. A tire filling bell of the tire filling station is arranged above the upper side of the horizontally lying wheel-tire combination. To inflate or fill the tire, the tire filling bell is lowered until the free bottom ring-shaped edge rim of the tire filling bell presses downwardly against the tire sidewall, and then continues to press the tire sidewall downwardly away from the wheel rim, so that an annular gap or space is formed between the tire sidewall bead and the wheel rim. Pressurized air is then filled through the filling bell and through the annular gap between the tire sidewall and the wheel rim into the inner space of the wheel-tire combination. As the air pressure builds up within the tire, the air pressure expands the tire, and thereby pushes the tire sidewall outwardly or upwardly into sealing contact with the wheel rim, while closing the above mentioned annular gap.
Further according to the above mentioned patent reference, the apparatus actually comprises two tire filling bells or rings of different diameters, which are arranged concentrically nested within one another and axially slidably relative to one another. Thereby, either one of the filling rings (respectively having different diameters) can be selected, to better match the diameter of the wheel-tire combination that is to be filled. Thus, the single apparatus can be used to fill different sizes, i.e. different diameters, of tires and/or wheel rims.
In practice, each one of the two filling rings of the conventional apparatus is typically used to fill respective wheels having three different successive rim sizes. Thus, with the two different sizes of filling rings, the known apparatus can be used to fill a total spectrum of six different sizes, i.e. diameters, of mounted tires. Efficiency and economy of operation in the use of such tire filling stations requires that a single station must be able to service the greatest possible number of different wheel-tire sizes. Furthermore, purchasers of such tire filling stations are requiring ever higher levels of quality with respect to the accuracy and reproducibility of the tire inflation pressure achieved by the tire filling stations. It has been found in practice, however, that these increasing quality demands cannot always be satisfied if three different successive rim sizes of wheels/tires are to be serviced with a single tire filling bell or ring, because the precision of the size match is not sufficient and the accuracy of the resulting tire inflation pressure is thereby impaired.
An earlier conventional tire filling apparatus of the abovementioned general type, without size adaptability, is disclosed in U.S. Pat. No. 4,947,919 (Timlin—August 1990).
Another conventional size-adjustable tire filling station includes a wheel rim seal ring, for sealing against the wheel rim to close off the interior space of the wheel rim during the tire filling process, for example as disclosed in the German Patent DE 198 01 455.
The entire disclosures of the two abovementioned U.S. Pat. Nos. 6,467,524 and 4,947,919 are incorporated herein by reference.